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SERVICE MANUAL
for the
OVER-THE-RANGE
MICROWAVE OVEN HOOD
COMBINATION
1997 “E” Models
March, 1997 Printed in U.S.A. LIT4322167
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THIS MANUAL CONTAINS INFORMATION NECES- SARY FOR SERVICING THE WHIRLPOOL MICRO- WAVE OVEN HOOD COMBINATION , MODELS: MH7130XE MH7135XE MH9115XE THE MANUAL IS DESIGNED TO BE USED ONLY BY QUALIFIED SERVICE PERSONNEL. THE SERVICE INFORMATION IS ORGANIZED TO HELP YOU EAS- ILY FIND WHAT YOU NEED. CHECK YOUR LOCAL BUILDING CODE FOR THE PROPER MODE OF INSTALLATION. IN THE AB- SENCE OF LOCAL CODES, THIS UNIT SHOULD BE INSTALLED IN ACCORDANCE WITH THE NATIONAL ELECTRICAL CODE, ANSI/NFPA NO. 70 - 1990, OR
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page iii TABLE OF CONTENTS Page Important Safety Information ...............................................................................................................................v Theory Of Operation ......................................................................................................................................... 1-1 Component Access ...................
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Page Component Description & Testing .................................................................................................................. 3-1 Important Safety Instructions .................................................................................................................... 3-1 The Thermal Fuses..................................................................................................................................... 3-4 The Blower Motor Capacitor ...........
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page v IMPORTANT SAFETY INFORMATION This service manual is intended for factory- service technicians only. We recommend that WARNING customers DO NOT service their own units, because of the complexity and risk of high- Fire Hazard voltage electrical shock. Do not obstruct the flow of ventilation air. The following information is used throughout this manual, and should be read carefully
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CAUTION WARNING TO SERVICE TECHNICIANS To avoid possible exposure to microwave ra- • Proper operation of the microwave ovens diation or energy, visually check the oven for requires that the magnetron be properly damage to the door and door seal before assembled to the waveguide and cavity. operating the oven. Use your microwave sur- Never operate the magnetron unless it is vey meter to check the amount of leakage properly installed. before servicing. In the event that the
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page vii CAUTION Whirlpool microwave ovens have a monitoring system designed to assure proper operation WARNING of the safety interlock systems. The interlock monitor switch will immediately DISCONNECT FROM POWER SUPPLY cause the oven fuse to blow if the door is BEFORE SERVICING. opened while the following combined failure exists: CAUTION: HIGH VOLTAGES ARE Primary door interlock switc
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R.F. LEAKAGE TEST When checking for R.F. Ieakage, use an ap- proved R.F. measuring device to assure less CAUTION 2 than 4 mw/cm emission at 5 cm distance with a maximum scan rate of 2.5 cm/second, in EQUIPMENT compliance with U.S. Government Department • Electromagnetic energy leakage monitor of Health, Education and Welfare 21 CFR1030, (NARDA 8100B, HOLADAY H1501). performance Standard for Microwave Ovens. • 600 ml glass beaker. A properly operating door and seal assembly • Glass thermometer 10
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Cooking Products Service Manual Original March 1997 4322167 © 1997 Whirlpool Corporation Page 1-1 THEORY OF OPERATION Relay 4 controls the speed of the blower motor The microwave oven is powered by the 120- through the contol panel. The base thermal volt line. Whenever the door is closed and a fuse will also turn the blower motor on to its cooking function is programmed through the low speed if the temperature reaches 133˚F. control panel’s keypad, relay contacts on the The
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The normally-closed (N.C.) contacts of relay 4 provide a potential circuit for the Base Thermal Fuse. If the base of the oven exceeds 133˚F, the thermal fuse contacts close, and a circuit for the low-speed side of the blower motor is completed, which turns the motor on. The low-speed blower will operate until the base temperature drops below 104˚F and opens the thermal fuse contacts, and turns off. N L1 MICROCOMPUTER BOARD 20A LINE LOW-VOLTAGE FUSE TRANSFORMER W RD BK BK BK 3 1 MAGNETRON CAVITY
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page 2-1 COMPONENT ACCESS COMPONENT SECTIONS This section instructs you on how to service • The Operating Control System the individual components in the Microwave Oven Light Socket Oven Hood Combination. These components Control Circuit Board (shown below) and their sections are as fol- Turntable Indicator Circuit Board lows: Fan Motor Power Cord • General Blower Motor Capacitor Cabine
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GENERAL REMOVING THE MICROWAVE OVEN & CABINET 4. Support the front of the microwave oven and remove the two bolts and washers WARNING from the top of the oven. Personal Injury Hazard Disconnect from the electrical supply be- fore servicing the unit. Failure to do so could result in death or electrical shock. IMPORTANT NOTE: Most of the microwave components can be serviced without remov- ing the unit or its cabinet. They can be ac- cessed by removing the vent grille and the control panel. Before
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page 2-3 VENT GRILLE CABINET SCREWS (2) POWER SCREW CORD VENT CABINET GRILLE TAB SLOTS POWER CORD COVER CABINET SCREWS SLOTS BASE PLATE BASE PLATE CONNECTORS SCREWS (6) COOKTOP LIGHT ASSEMBLY WIRING Removing The Cabinet 2-3
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THE PROTECTION CONTROL SYSTEM REMOVING THE OVEN DOOR 2. Remove the two screws from the top of the cabinet for the vent grille and remove WARNING the grille (see the illustration on page 2-3). Personal Injury Hazard 3. Open the oven door all the way, then lift the door pins out of the hinge holes and Disconnect from the electrical supply be- remove it. fore servicing the unit. Failure to do so could result in death or electrical shock. 4. Install the new oven door and the vent grille on the micro
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page 2-5 REMOVING THE OVEN DOOR COMPONENTS 4. To remove the oven door choke, use a putty knife along the edges, and pry the WARNING choke out from around the inside window frame. Personal Injury Hazard Disconnect from the electrical supply be- fore servicing the unit. Failure to do so could result in death or electrical shock. OVEN DOOR 1. Disconnect the electrical supply to the microwa
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REMOVING THE CONTROL PANEL 2. Remove the two screws from the top of the cabinet for the vent grille and remove WARNING the grille (see the illustration on page 2-3). Personal Injury Hazard 3. Remove the screw from the top center tab Disconnect from the electrical supply be- of the control panel, then lift the panel so fore servicing the unit. Failure to do so that the bottom tabs are out of the slots could result in death or electrical shock. and pull it forward. 4. Turn the panel over and disco
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page 2-7 REMOVING THE LINE FUSE 2. Remove the two screws from the top of the cabinet for the vent grille and remove WARNING the grille (see the illustration on page 2-3). Personal Injury Hazard 3. Remove the control panel from the micro- Disconnect from the electrical supply be- wave oven (see page 2-6). fore servicing the unit. Failure to do so 4. From inside the control panel opening,
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REMOVING/ADJUSTING THE INTERLOCK SWITCHES 6. One at a time, pull the wire connectors off the defective switch, and reconnect them WARNING to the same terminals on the replacement switch. Personal Injury Hazard 7. Snap the new switch into place on the Disconnect from the electrical supply be- switch housing. fore servicing the unit. Failure to do so could result in death or electrical shock. 8. Mount the interlock switch assembly to the chassis flange with two screws. REMOVING A SWITCH 9. Close t
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Cooking Products Service Manual Original March, 1997 4322167 © 1997 Whirlpool Corporation Page 2-9 INSET 2 1. PUSH THIS LOCKING ARM BACK TO UNLOCK INSET 1 SWITCH. 1. RAISE THIS LOCKING ARM TO RELEASE SWITCH FROM HOUSING. ALL OTHER 2. PRESS BODY IN SECONDARY SWITCHES INTERLOCK THIS DIRECTION TO SWITCH REMOVE SWITCH 2. ROTATE SWITCH ON THIS FROM HOUSING. PIN AND REMOVE SWITCH FROM HOUSING. NOTE: THESE POSTS HOLD THE SWITCH IN PLACE ON THE HOUSI
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REMOVING THE BASE THERMAL FUSE 2. Remove the two screws from the top of the cabinet for the vent grille and remove WARNING the grille (see the illustration on page 2-3). Personal Injury Hazard 3. Remove the control panel from the micro- Disconnect from the electrical supply be- wave oven (see page 2-6). fore servicing the unit. Failure to do so 4. Remove the mounting screws from the could result in death or electrical shock. base thermal fuse and remove it. 1. Disconnect the electrical supply to
